<script src="jquery-1.8.2.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
  $('#selectAll').click(function(){
      if($(this).is(':checked')){
        $('.frm').each(function(){
          $(this).attr('checked',true);
        })
        $('#show').show();
      } else {
        $('.frm').each(function(){
          $(this).attr('checked',false);
        })
        $('#show').hide();
      }
  })
});
</script>

<input type="checkbox" id="selectAll" >Select/Deselect All<br>
<input type="checkbox" class="frm" >One<br>
<input type="checkbox" class="frm" >Two<br>
<input type="checkbox" class="frm" >Three<br>
<input type="checkbox" class="frm" >Four<br>
<input type="checkbox" class="frm" >Five<br>
<input type="checkbox" class="frm" >Six<br>
<input type="checkbox" class="frm" >Seven<br>
<input type="checkbox" class="frm" >Eight<br>
<input type="checkbox" class="frm" >Nine<br>
<input type="checkbox" class="frm" >One<br>
<input type="checkbox" class="frm" >Two<br>
<input type="checkbox" class="frm" >Three<br>
<input type="checkbox" class="frm" >Four<br>
<input type="checkbox" class="frm" >Five<br>
<input type="checkbox" class="frm" >Six<br>
<input type="checkbox" class="frm" >Seven<br>
<input type="checkbox" class="frm" >Eight<br>
<input type="checkbox" class="frm" >Nine<br>
<input type="checkbox" class="frm" >One<br>
<input type="checkbox" class="frm" >Two<br>
<input type="checkbox" class="frm" >Three<br>
<input type="checkbox" class="frm" >Four<br>
<input type="checkbox" class="frm" >Five<br>
<input type="checkbox" class="frm" >Six<br>
<input type="checkbox" class="frm" >Seven<br>
<input type="checkbox" class="frm" >Eight<br>
<input type="checkbox" class="frm" >Nine<br>

<span id="show" style="display:none">
  <a href="#">Delete All</a>
</span>
